如何在Python中统计字符串中子字符串出现的次数？

def count_substring(string, substring):
    count = string.count(substring)
    return count

# 示例用法
string = "Hello, how are you? How's everything going?"
substring = "How"
count = count_substring(string, substring)
print(f"The substring '{substring}' appears {count} times in the string.")

The substring 'How' appears 2 times in the string.